In Vitro and In Vivo Analyses of 14-O-Acylanthracyclines

描述（由申请人提供）：14- o -酰基蒽环类药物，以N-benzyladriamycin-14-valerate （AD 198）和N-benzyladriamycin-14-pivalate （AD 445）为代表，在功能上不同于阿霉素（DOX）和其他dna结合的蒽环类药物。AD 198和AD 445定位于细胞质中，特异性结合蛋白激酶C （PKC）的C1调节结构域，激活PKC，快速触发增殖细胞的凋亡。如我们所示，AD 198和AD 445激活线粒体相关的PKC-d全酶，在32D触发线粒体膜去极化和细胞色素c释放。3个常规髓样细胞。与非pkc结合的蒽环类药物如DOX、AD 198和AD 445不同，在多种细胞类型中，细胞毒性不受Bcl-2或Bcl-XL抗凋亡蛋白表达或p53蛋白功能障碍的影响。AD 198和AD 445也绕过了多药转运蛋白和拓扑异构酶II活性改变所带来的耐药。在体内，AD 198显示出比DOX更强的杀肿瘤活性，骨髓抑制减少，没有明显的器官毒性，包括缺乏心脏毒性。该提案描述了AD 198和AD 445的下一阶段分析，从而导致临床试验。本研究的总体目标是首先分析PKC被AD 198和AD 445激活导致快速凋亡的机制。我们将从32D开始。以确定药物诱导的PKC-d激活如何以不受Bcl-2或Bcl-XL状态影响的方式导致线粒体去极化和细胞色素c释放。第二，鉴于迄今为止这些药物在体外和体内的明显优势

DESCRIPTION (provided by applicant): The 14-O-acyl anthracyclines, represented by N-benzyladriamycin-14-valerate (AD 198) and N-benzyladriamycin-14-pivalate (AD 445), are functionally distinct from doxorubicin (DOX) and other DNA-binding anthracyclines. AD 198 and AD 445 localize in the cytoplasm, specifically bind to the C1 regulatory domain of protein kinase C (PKC) and activate PKC in a manner that rapidly triggers apoptosis in proliferating cells. As we have shown, AD 198 and AD 445 activate mitochondrial-associated PKC-d holoenzyme to trigger mitochondrial membrane depolarization and cytochrome c release in 32D.3 routine myeloid cells. Unlike non-PKC binding anthracyclines, such as DOX, AD 198 and AD 445 cytotoxicity is unaffected by Bcl-2 or Bcl-XL anti-apoptotic protein expression or p53 protein dysfunction in a variety of cell types. AD 198 and AD 445 also circumvent resistance conferred by multidrug transport proteins and altered topoisomerase II activity, In vivo, AD 198 demonstrates tumoricidal activity greater than DOX, with reduced myelosuppression and no significant organ toxicity, including a lack of cardiotoxicity. This proposal describes the next stages of analysis of AD 198 and AD 445 leading to clinical trials. The overall goals of this study are first, to analyze the mechanism by which PKC activation by AD 198 and AD 445 leads to rapid apoptosis. We will begin with 32D.3 cells to determine how drug-induced PKC-d activation leads to mitochondrial depolarization and cytochrome c release in a manner that is unaffected by Bcl-2 or Bcl-XL status. Second, given the clear advantage of these agents over DOX thus far in vitro and in vivo, we will continue these studies by assessing the in vivo efficacy of AD 198 an d AD 445 against implanted HL60 human leukemia cells expressing a variety of resistance mechanisms (Bcl-21P-gplMRPIp53-1-). Completion of these studies will establish in greater detail a mechanism of AD 198 and AD 445 induction of apoptosis and determine whether these novel agents can circumvent multiple, clinically relevant mechanisms of drug resistance in vivo.